feat: IMAP mail sync with thread-to-contact matching (PRD §6.1)

Real IMAP connection via imapflow library:
- Connects to IMAP server (IMAPFlow, TLS on port 993)
- Fetches recent messages (configurable limit, default 20)
- Extracts: from, fromEmail, subject, date, snippet (200 chars)
- Thread-to-contact matching (PRD §6.1):
  1. Match sender email against persons table
  2. If no person match, extract domain and match against company.website
  3. Returns matchedCompany + matchedPerson for each email
- Audit-logged (action: crm.mailsync:imap)
- Zod validated (host, port, user, password, folder, limit)
- 502 on IMAP connection failure with detail
- 400 on validation failure

Tested: invalid creds → 502 'IMAP connection failed', missing host → 400

skills/design/design-templates/wechat-cover-pair/SKILL.md

@@ -0,0 +1,52 @@
+---
+name: wechat-cover-pair
+description: 微信公众号封面对模板 — 主图（headline + subline + 视觉锚点）+ 次图/分享图（短标题 + logo / 账号标签）+ 长图头（文章标题 + 章节预览）。比小红书封面要求更强的标题腿粗、更明确的安全区、更克制的阅读节奏。必须按当前微信尺寸读 canvas-and-device.md。触发："做个公众号封面 / 微信首图次图对 / 视频号封面 / 公众号分享图 / 长图头"。NOT XHS 3:4 尺寸，NOT XHS 贴纸密集风。
+visibility: public
+mode: template
+carrier: fixed-image
+scenario: social-content
+pattern_source: pattern.html
+source_priority: skill-first
+triggers:
+  - "做个公众号封面"
+  - "微信首图次图对"
+  - "视频号封面"
+  - "公众号分享图"
+  - "长图头封面"
+  - "微信生态封面"
+related_patterns: social-card-editorial
+---
+
+# WeChat Cover Pair Template
+
+Use for 微信公众号首图、封面图、分享图、视频号/微信生态封面等 fixed-image surfaces.
+
+## Core Rule
+
+WeChat covers are not Xiaohongshu covers. They need stronger headline legibility, clearer safe areas, and a calmer reading rhythm.
+
+## Structure Options
+
+- main cover: headline + subline + visual anchor
+- secondary cover: shorter title + logo/account label
+- long image header: article title + section preview
+- cover pair: large main cover + smaller share-safe variant
+
+## Must Do
+
+- Read `canvas-and-device.md` for current WeChat dimensions and safe areas.
+- Keep title readable in thumbnail contexts.
+- Avoid placing important text too close to edges.
+- Do not assume XHS 3:4 dimensions.
+
+## Avoid
+
+- XHS-style crowded sticker layouts.
+- Long headline squeezed into one line.
+- Tiny subtitle that disappears in feed preview.
+
+## Pattern Source Rule
+
+Read this `SKILL.md` first. Do **not** read `pattern.html` by default.
+
+Read `pattern.html` only when you need concrete layout rhythm, spatial relationships, or interaction/annotation behavior that this markdown cannot fully specify. When read, extract patterns only; do not copy DOM, CSS classes, exact spacing, placeholder copy, or styling wholesale.